It comes after an application for Mr McGowan and Attorney-General John Quigley to give evidence remotely after the extension of the state's hard border measures.
Alternatively, Justice Michael Lee was asked to delay the start of the trial.
Mr Palmer is suing the Mr McGowan in the Federal Court claiming public comments, including labelling him the "enemy of West Australia", had damaged the businessman's reputation.
The premier has lodged a counter-claim claiming the billionaire defamed him in several interviews.
During an urgent interlocutory hearing on Wednesday Justice Michael Lee agreed to delay the trial - due to start on Monday - until February 14.
But he insisted Mr McGowan appear in person from February 26 to 28 to give evidence.
Justice Lee earlier described video-link hearings as "suboptimal", stressing his "firm preference" for litigants, particularly the parties and in defamation cases, was to give evidence in person.
"I want to go back to having trials in the usual way," he said.
Mr McGowan told the court he would be able to self-quarantine on his return to WA, but had Parliament sitting days, national cabinet and other meetings with some best attended in person.
He could be permitted to attend official duties, but any person he had direct contact with would also have to quarantine for 14 days, he said in an affidavit.
"If I were to attend Parliament during a mandatory quarantine period then each person present in the Legislative Assembly would fall within the above definition of an extreme risk contact and be required to complete 14 days mandatory quarantine," Mr McGowan added.
The premier said he did not want to ask to be subject to conditions different to those that apply to other West Australians and would not ask to attend parliament during the quarantine period.
"This is because, given the high number of COVID cases in New South Wales, I consider the risk of advertently transmitting the virus to someone in Parliament is too high and the consequences of an outbreak in Parliament would be severe," he said in the affidavit.
Mr McGowan announced in December the hard border controls would ease from February 5, but last week delayed the opening due to concerns about the Omicron strain of COVID-19.
A state government spokesperson said Mr McGowan's appearance later in February would enable him to quarantine without interfering with parliament sitting days.
"The premier welcomes this result as it allows him to carry out his responsibilities unimpeded, at an important time at which the Omicron variant and its impact on Western Australia requires the full attention of the Western Australian government," the spokesperson told AAP.
Earlier, Justice Lee said he would not deny anyone access to his courtroom because of their vaccination status.
Mr Palmer's lawyers understood the court's protocols required anyone coming into the room to be vaccinated, but the businessman has revealed publicly he was not vaccinated.
Justice Lee said this was incorrect.
Background to the case includes claims relating to the circumstances surrounding WA legislation which prevented Mr Palmer and his company Mineralogy from suing the state for billions of dollars.
Mr Palmer in October lost his High Court battle with WA over the legislation preventing him and his company Mineralogy from suing the state.
He was seeking up to $30 billion from WA taxpayers, claiming legislation, introduced by the McGowan Labor government and hastily passed with the support of opposition parties, is unconstitutional.